Anti-NMDA-receptor encephalitis in Filipino adults: Case series and outcomes in a tertiary government hospital in the Philippines

ABSTRACT

INTRODUCTION@#We performed a case series of all five (5) confirmed adult Filipino cases of Anti-N-Methyl-D-Aspartate receptor (anti-NMDA-R) encephalitis in a tertiary government hospital in the Philippines admitted in the past three years. Two cases were identified with unique features (1) a 23-year old female who presented with combined refractory seizures and persistent chorea and orofacial dyskinesias; and (2) a 22-year old male who presented with refractory epilepsia partialis continuua. The rest of the patients were hereby presented.@*BACKGROUND@#In the past years, anti-NMDA-R encephalitis has been considered a diagnosis of exclusion in lieu of other infectious causes of encephalitis. It is rare and an emerging disease with an incidence estimated at approximately 2-3 cases per million. Recent literature recorded severe cases of anti-NMDA-R encephalitis that presented as intractable first onset seizures, combined with hyperkinetic movement disorders, acute psychosis without a premorbid condition, and dysautonomia. @*OBJECTIVES@#To present the clinicodemographic profile and to discuss the management and outcomes of patients with anti-NMDAR encephalitis in a tertiary hospital in the Philippines.@*RESULTS@#Here, we report five confirmed cases of anti-NMDA-R encephalitis admitted in 2019-2021. The mean age is 23 years old, with 41 female to male ratio with a median length of hospitalization of 58 days. All patients presented with acute psychiatric symptoms without premorbid condition, focal and generalized seizures, decreased consciousness, dyskinesias, and autonomic instability. Four patients needed airway support for central hypoventilation, one had first onset seizure that developed into refractory epilepsia partialis continuua, one had persistent chorea and orofacial dyskinesia. Imaging studies of the brain included contrast-enhanced CT Scan and MRI with unremarkable findings. No female patients had an ovarian teratoma as revealed in the whole abdominal ultrasound. All CSF analysis for anti-NMDA-receptor was done in the same laboratory outside the hospital which revealed positive for NMDA-receptor antibodies, while CSF lymphocytic pleocytosis was only seen in 1/5 and protein elevation in 4/5. All of the patients underwent electroencephalogram (EEG) studies which revealed diffuse delta-theta slowing without epileptiform discharges. The patient who had persistent chorea and orofacial dyskinesias showed extreme delta brush, while one had normal EEG findings. They all received high-dose steroid and intravenous Immunoglobulin (IVIg); three patients were able to undergo Rituximab infusion. Only one female patient had mild deficits, one female was discharged fully functional and ambulatory from being weaned off from the mechanical ventilator, one female had aborted cardiac arrest and was discharged bedridden at GCS 10, and two died due to the other concomitant medical conditions. The Modified Rankin Scale (MRS) and Mini-mental Status Examination (MMSE) were used to assess the neurological and functional outcomes of our patients. @*CONCLUSION@#Anti-NMDA-R encephalitis is an emerging neurological disorder that warrants early identification as it impacts timeliness of management and long-term outcomes.